Multi-stage air blower



Dec. 21, 1965 J STR|KE ET AL MUL'II-STAGE AIR BLOWER 2 Sheets-Sheet 1 Filed Jan. 29, 1965 WM W N INVENTORS JOHN L. SUP/K5 GEORGE Fl 00'? 6,4. fim/ Dec. 21, 1965 J. L. STRIKE ET L MULTI-STAGE AIR BLOWER 2 Sheets-Sheet 2 Filed Jan. 29, 1965 JOHN L. 5

BYGEORGE /v. F100,?

ATTORNEY United States Patent 3,224,667 MULTI-STAGE AIR BLOWER John L. Strike and George N. Floor, Salt Lake City, Utah, assignors to McGraw-Edison Company, Elgin, 111., a corporation of Delaware Filed Jan. 29, 1965, Ser. No. 428,952 1 Claim. (Cl. 230130) This invention relates to a multi-stage air blower.

An object of the invention is to provide an air blower that comprises similar stage sections arranged longitudinally between an air inlet and an air outlet at the ends of a casing, thereby providing a machine that can be produced with different numbers of stages at minimum expense.

Another object of the invention is to provide an air blower, as above characterized, in which each stage comprises a stator with a rim that is in nesting engagement with an adjacent stator to space the stators from each other uniformly, and comprises a shaft-mounted rotor that is spaced from an adjacent rotor by spacers on the rotor shaft that have a length exactly equal to the space between adjacent stators, the rotor of each section being disposed between adjacent stators, and the rotors and stators being alternate.

A further object of the invention is to provide an air blower, as above, in which the spacers between the rotors rotate with said rotors and extend through clearance openings provided in the stators.

A further object of the invention is to provide an air blower in which the rotors and stators are provided with air-moving and compressing blades that are sandwiched between plates that are transversely arranged with respect to the shaft, one plate of each stator being affixed to the casing, one plate of each rotor being clamped between and, therefore, fixedly connected to the shaft, the other plate of each stator and rotor being formed as a ring with air-passing clearance with the shaft and spacers thereon.

A still further object of the invention is to provide an air blower, as above characterized, that includes novel and improved means for coupling one end of the blower shaft to a drive motor.

A yet further object of the invention is to provide the stator with means for smoothening the fiow of air to the rotor on the down-stream side.

This invention also has for its objects to provide such means that are positive in operation, convenient in use, easily installed in a working position and easily disconnected therefrom, economical of manufacture, relatively simple, and of general superiority and serviceability.

The above objects are realized in a blower construction that comprises stage sections made up of stator and rotor components which, for each section, are the same, a casing that mounts the stators and varies in length only and according to the number of stage sections of which the blower is comprised, and a shaft that varies in length according to the number of rotors which it mounts. Except as operatively mounted, as above, the air-moving and compressing vanes of the stator are oppositely curved, said vanes being sandwiched between transverse discs, one disc of each stator and of each rotor having airpassing clearance around the shaft and spacers thereon between the rotors carried by the shaft. One end of the shaft is threaded for a nut that clamps the rotors and 3224,67 Patented Dec. 21, 1965 their spacers in stacked relation against a shoulder on the opposite end of the shaft. Mounting pillow blocks are provided at each end, one block comprising a bearing for the driven end of the shaft, and the other block comprising a bearing for a sleeve extension of the clampnut. End walls enclose the casing and are afiixed to the pillow blocks, the casing, adjacent said walls, being provided with similar spouts that constitute the intake and outlet of the blower.

The invention also comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description and which is based on the accompanying drawing. However, said drawing merely shows, and the following description merely describes, preferred embodiments of the present invention, which are given by way of illustration or example only.

In the drawing, like reference characters designate similar parts in the several views.

FIG. 1 is a broken longitudinal section view of a multistage air blower showing features of the present invention.

FIG. 2 is an elevational view, partly in longitudinal section, showing a multi-stage blower of modified construction.

FIG. 3 is a broken face view of the intake side of a stator used in the present construction.

FIG. 4 is a similar view of a rotor.

FIG. 5 is a fragmentary sectional view of a modified form of stator.

The multi-stage air blower shown in FIG. 1 comprises, generally, a cylindrical casing 10, a driven shaft 11 extending axially through said casing, pillow blocks 12 and 13 at opposite ends of the casing to journal said shaft and affixed to and non-rotationally carrying the casing, inlet and exhaust spouts 14 and 15 afiixed to the opposite ends of the casing, and a plurality of stage sections 16 within the casing for moving air from said inlet or intake 14, compressing said air and discharging the same from the exhaust or outlet 15.

The casing 10 is formed of a sheet of steel or other suitable metal 20, the same being formed into a cylinder and lapped at 21. The length of the casing will vary according to the number of stations of which the blower will comprise, the variations being on fixed length increments according to the length that the stations occupy and their longitudinal spacing. At one end, an end bell 22 closes the end of cylindrical casing wall 20, the inlet spout 14 being provided in register with an opening 23 in said sheet wall 20. At the other end, an end bell 24 closes the casing wall 20, a spacer ring 25 being interposed between the outer cylindrical face of the bell 24 and the wall 20.

An inlet stator ring 26 extends inwardly from the bell 22 at the inlet end, is provided with an opening registering with the opening 23, and is provided with a wall 2'7 with an air inlet opening 28 around the shaft 11. An outlet stator ring 29 is afiixed to and extends inwardly from the bell 24 at the outlet end.

The shaft 11 is journalled, at its end 30 that is connected to a drive motor or the 'like, in pillow block 12. Said pillow block is also fixedly connected to the outside of the end bell 22. Thus, the casing is fixed against rotation while the shaft '11 rotates. Said shaft has an enlargement 31 that extends through a 'hole in said bell 22, the inn-er end of said enlargement defining a shoulder 31a that faces toward the opposite end of the blower.

Said shaft 11 continues from the enlargement 31 thereof as an elongated rotor-mounting part 32 which extends through an opening in the end bell 24 and is provided with external threads 33 at said end. A reduced extension 34 of the shaft extends into the pillow block 13 which has a closed end 35. Pillow block 13 is fixedly connected to the end bell 24 in substantially the same manner as the connection between pillow block 12 and end bell 22.

The outlet stator ring 29 and the casing sheet 20 are provided with registering openings similar to the openings 23 at the inlet end of the blower, the same being in communication with the outlet or exhaust spout 15.

The stage sections 16, as hereinbefore indicated, are alike and may vary in number according to the desired terminal pressure at the exhaust spout that is desired. Said sections are arranged in stacked relation between the wall 27 of the inlet stator 26 and the end bell 24 at the outlet end of the blower.

Each stage section 16 comprises a stator 35 (FIG. 3) that is aflixed, as by rivets 36, to the inner face of the casing cover 20, and a rotor 37 that is fixedly carried by the mounting part 32 of the shaft 11. The rotor at the inlet end is engaged against the shaft shoulder 31a, the other rotors are spaced apart by spacers 38 strung on the shaft part 32, a shorter spacer 39 is engaged against the rotor at the outlet end of the stack, and a nut 40, engaged with the shaft threads 33, clamps the described assemblage of rotors and spacers against said shoulder 31a. Said nut 40 may be locked against backing off by a bushing nut 41, also engaged with said threads 33 and extending over the shaft extension 34, as a bushing thereon.

Each stator 35 comprises a cup member 42, a disc 43 parallel to and spaced from said cup in a direction forward the inlet end of the blower, and a set of curved impeller blades 44 sandwiched between the disc wall 45 of the cup member and the disc 43. The latter has a hole 46 that has small clearance around the spacers 38, and an outer peripheral edge 47 that is inwardly spaced from an annular cup flange 48 that extends from the outer periphery of the disc wall 45 in a direction toward the inlet end of the blower. The wall 45 of the cup member has a central air-passing opening 49, the arrows 50 showing the air flow through said opening in each stage section. The blades 44 are coextensive radially with the coincidental annular portions of the disc 43 and the wall 45, as clearly shown in FIG. 3. The direction of curvature of said blades depends on the direction of rotation of the shaft 11 to effect air flow in a direction toward the axis, i.e., the shaft 11.

Each rotor 37 is similarly provided with parallel walls or discs 51 and 52, and with a set of impeller blades 53 similar to but oppositely curved with respect to the blades 44. The disc 51 has a central hole 54 that fits over the shaft part 32 and an outer peripheral edge 55 that is the same size as the edge 47 of the stator disc 43. The disc 52 has a central air-passing opening 56 the same size as opening 49 in disc 45 and its outer edge 57 is the same size as edges 47 and 55. The blades 53 have the same radial size as the blades 44. All of the stator and rotor blades have the same inner and outer diametral sizes.

The stators are stacked independently of the rotor, the free edge of each cup flange 48 being diametrally enlarged by the thickness of the sheet metal of which the cups 42 are formed so that said annular enlargements 58 fit over the corners 59 defined between the walls 45 and flange 48 of the next cup on the inlet side. The cup 42 next adjacent to the stator ring 26 fits over the corner 59 of said ring and all of the other cups, one after the other, fit in the same way over the cups on the intake side of the blower. The corner 59 of cup 42 at the outlet end is engaged by an enlargement 58 on the flange on the stator ring 29 to complete the stack of stators.

The length of the spacers 38 and of the flanges 48 to the enlargements 58 are equal. Therefore, the rotors, which are alternated with the stators, are suitably spaced.

Each station section 16 comprises a stator and a rotor, as above explained. However, at the outlet end, only a rotor is provided. Therefore, each blower has one more rotor than it has stators.

As shown at 60, spacer rings may be interposed between the outer cover 20 and the flanges 29 and 60.

The blower illustrated in FIG. 2 has a station section arrangement as above described but has a fewer number of sections 16. This blower, at one end, has a mounting connection to a motor 65 which, by means of a base fitting 66 is connected to an end bell 24 at one end of the blower 10a. The opposite end of said blower terminates at a plate 67 with a central opening 68 which is similar to the plate 27 and opening 28 of the earlier-described form. It will be clear that said blower 10a has but one support end and that the same may be horizontal, as shown, or at any other angular position.

The rotors 37 are mounted on the portion 69 of shaft 11 with clamping sleeves and shoulders, as above described. Said shaft extends beyond the bell 24 and is journalled in a bearing 70 provided in the base fitting 66. As before, the shaft end has threads 33 for a nut 40 which, rather than abutting the end sleeve 39, abuts the inner race 71 of the bearing 70. The arrangement is such that the shaft 69 and the rotors thereon are fully rotational with the inner race of the bearing 70.

The threaded end of the shaft 69 is hollow for the driven shaft 72 of the motor 65, a key 73 connecting the shafts 11 and 72.

As shown in FIG. 5, the wali 45 of each stator 35, at its air-passing opening, may be flared at 74 in a direction toward the adjacent rotor 37 to smoothen the air flow from the discharge of each stator to the inlet of each rotor.

While the foregoing has illustrated and described what is now contemplated to be the best mode of carrying out the invention, the constructions are, of course, subject to modification without departing from the spirit and scope of the invention. Therefore, it is not desired to restrict the invention to the particular forms of construction illustrated and described, but to cover all modifications that may fall within the scope of the appended claim.

Having thus described this invention, what is claimed and desired to be secured by Letters Patent is:

A multi-stage air blower comprising:

(a) a cylindrical casing of uniform diameter throughout its length with a rotor shaft on the axis of said casing, an inlet and outlet being provided at the opposite ends of the casing,

(b) a plurality of stators arranged in stacked interfitted relation,

(c) each stator comprising a cup member having a flange secured to the casing and a transverse wall having an air-passing axial opening, and a disc parallel to said wall and spaced longitudinally therefrom, the disc having an outer peripheral edge smaller than the diametral size of the flange, said flange having its free annular marginal edge portion laterally offset to increase the diameter of the flange at its marginal edge portion by the thickness of said flange to provide an enlargement fitting over the annular corner of an adjacent cup thereby defining annular spaced areas within the casing and between the adjacent cup flanges and the casing, filler bands occupying at least some of the annular areas of the spaces so defined,

(d) -a complement of stator blades between and connecting said wall and disc, the same having a radial extent between the edge of said air-passing opening of the wall and said outer peripheral edge of the disc,

(e) -a plurality of rotors carried by the shaft and alternating with the stators, each of said rotors being 5 provided with complements of impeller blades of the same radial extent as the stator blades,

(f) an end bell fixed to and closing one end of the casing and said rotary shaft extending through an axial opening in said bell, and

(g) a pillow block positioned adjacent said end bell to journal the rotary shaft end, said pillow block being fixed to said end bell and non-rotatably carrying said casing.

FOREIGN PATENTS France.

Great Britain. Italy. Switzerland.

DONLEY I. STOCKING, Primary Examiner.

HENRY F. RADUAZO, Examiner. 

